Mortality through 1990 among white male workers at the Los Alamos National Laboratory: considering exposures to plutonium and external ionizing radiation.

A cohort mortality study was conducted of 15,727 white men employed by the Los Alamos National Laboratory, a nuclear research and development facility. Some of the workers at this facility have been exposed to various forms of ionizing radiation and other potentially hazardous materials. These analyses focused on whole-body ionizing radiation exposures and internal depositions of plutonium. The results indicated that overall mortality among this cohort is quite low, even after nearly 30 y of follow-up. No cause of death was significantly elevated among plutonium-exposed workers when compared with their unexposed coworkers; however, a rate ratio for lung cancer of 1.78 (95% CI = 0.79-3.99) was observed. A case of osteogenic sarcoma, a type of cancer related to plutonium exposure in animal studies, was also observed. Dose-response relationships for whole-body dose from external ionizing radiation and tritium were observed for cancers of the brain/central nervous system, the esophagus, and Hodgkin's disease.

Mortality among a cohort of workers monitored for 210Po exposure: 1944-1972.

This study represents the largest epidemiologic investigation of humans exposed to the radionuclide 210Po. In a cohort of 4402 white males employed by the Mound Facility, during the period when Po operations were conducted (1944-1972), no excess mortality was observed. Among workers initially hired during World War II, mortality was elevated, especially for deaths from all cancers, cancers of the lung, and cancers of the rectum. These adverse health events do not appear related to exposure to 210Po. Among workers monitored for 210Po, mortality was significantly less than expected, although more lung cancers were observed than expected. No significant dose-response trends were identified for all causes combined, all cancers combined, or for cause-specific cancers among the Po-monitored subcohort. Continued follow-up of this cohort is planned.

Mortality among workers exposed to external ionizing radiation at a nuclear facility in Ohio.

In a cohort mortality study of white men employed by the Mound Facility (1947 through 1979), observed deaths did not exceed those expected based on US death rates for the overall cohort or for the subcohort monitored for external ionizing radiation. Among the radiation-monitored subcohort, mortality for workers with cumulative radiation doses of at least 10 mSv was not significantly increased when compared with mortality for coworkers with cumulative doses of less than 10 mSv. A significant dose-response based on a Mantel-Haenszel test of trend was observed for all leukemias. However, when a death from chronic lymphatic leukemia, a type of leukemia generally not regarded as radiogenic, was removed from the analyses, the strength of the dose-response was reduced.